feat: placeholder images, Nostr inbox, order lookup, SEO, bigger logo

- 5 SVG placeholder product images (minimal dark style with watermark initials)
- Seed data updated to reference .svg placeholders
- Nostr DM inbox in admin (Messages tab) with shop npub display
- GET /api/admin/nostr-info endpoint for shop pubkey
- My Orders page: customers look up orders by NIP-07 Nostr identity
- GET /api/orders/by-pubkey/:pubkey endpoint with hex validation
- SeoMeta component for OG/Twitter meta tags
- SEO meta on HomeView and ProductView
- Base OG meta tags in index.html
- "My Orders" link in shop header nav
- Splash logo doubled in size on desktop (680px max)

Co-Authored-By: Claude Opus 4.6 (1M context) <noreply@anthropic.com>

server/routes/ordersByPubkey.ts

@@ -0,0 +1,45 @@
+import { Router } from 'express'
+import { getDb } from '../db/connection.js'
+import type { OrderItem, OrderStatus } from '../../shared/types.js'
+
+export const ordersByPubkeyRouter = Router()
+
+interface OrderRow {
+  id: string
+  nostr_pubkey: string | null
+  email: string | null
+  btcpay_invoice_id: string | null
+  status: string
+  items: string
+  total_sats: number
+  note: string | null
+  created_at: string
+  updated_at: string
+}
+
+ordersByPubkeyRouter.get('/:pubkey', (req, res) => {
+  const pubkey = req.params.pubkey
+
+  if (!/^[0-9a-f]{64}$/.test(pubkey)) {
+    res.status(400).json({ error: { code: 'INVALID_PUBKEY', message: 'Invalid hex pubkey' } })
+    return
+  }
+
+  const db = getDb()
+  const rows = db.prepare(
+    'SELECT * FROM orders WHERE nostr_pubkey = ? ORDER BY created_at DESC'
+  ).all(pubkey) as OrderRow[]
+
+  res.json(rows.map((row) => ({
+    id: row.id,
+    nostrPubkey: row.nostr_pubkey,
+    email: row.email,
+    btcpayInvoiceId: row.btcpay_invoice_id,
+    status: row.status as OrderStatus,
+    items: JSON.parse(row.items) as OrderItem[],
+    totalSats: row.total_sats,
+    note: row.note,
+    createdAt: row.created_at,
+    updatedAt: row.updated_at,
+  })))
+})